1. Field of the Invention
The present invention relates in general to a mold assembly for molding an automotive seat, and more particularly to a mold assembly for molding an automotive seat which is formed with holes for inserting thereinto holding pins of a headrest. More specifically, the present invention is concerned with a mold assembly which is designed to achieve an exact die matching.
2. Description of the Prior Art
In order to clarify the task of the present invention, one of conventional mold assemblies of the above-mentioned type will be described with reference to FIGS. 4 and 5.
FIG. 4 shows a backrest pad 1 of an automotive seat, which is molded by means of the conventional mold assembly as shown in FIG. 5. The backrest pad 1 is molded from foamed polyurethane and constructed to have at a back side thereof a large rectangular recess 1b for setting therein a frame structure (not shown). The pad 1 has at its upper side an overhang portion 1a projected toward a lower side of the pad. The upper side of the pad 1 is formed with two holes 1c and 1c which extend to the recess 1b.
Although not shown in the drawings, a rectangular frame structure is put into the recess 1b to constitute a structural base of the backrest. The frame structures have two cylindrical holders mated with the holes 1c and 1c of the pad 1. An outer skin member covers the pad 1 and a back garnish covers a back side of the pad 1.
The mold assembly for molding the backrest pad 1 comprises, as shown in FIG. 5, generally two major parts which are a lower mold 2 having a cavity formed therein, an upper mold 3 adapted to be put on the lower mold 2, and a core 4 adapted to be put in the cavity of the lower mold 2. The core 4 has an outer shape in coincidence with the shape of the recess 1b of the molded pad 1. A pair of projections 2a are provided on a given portion of the inner side of the lower mold 2, and a pair of tubular portions 4a are integrally formed on the core 4. Upon proper assembly, the lower mold 2 receives therein the core 4 having the projections 2a neatly received in the tubular portions 4a.
A foamable material, such as a material for foamed polyurethane or the like, is poured into a clearance defined in the cavity about the core 4 and cured for a given time. After hardening of the material, the upper mold 3 and the core 4 are removed from the lower mold 2. With this, the backrest pad 1 is produced, which has two holes 1c and 1c produced by the mated projections 2a and the tubular portions 4a.
However, the above-mentioned mold assembly has the following drawback due to its inherent construction.
That is, the work for properly setting the core 4 in the lower mold 2 should be made by moving the core 4 awkwardly axially, laterally and vertically in the mold 2 for achieving coupling of the tubular portions 4a with the projections 2a. In other words, an operator has to work blindly to couple the tubular portions 4a with the projections 2a. Obviously, this is very troublesome and difficult.